1. Rosaceae (蔷薇科)
2. Amygdalus (桃属)
3. Amygdalus mongolica (蒙古扁桃)

Prunus mongolica Maximowicz, Bull. Soc. Imp. Naturalistes Moscou 54: 16. 1879.

Shrubs 1–2 m tall. Branches spreading, much branched; branchlets reddish brown when young, grayish brown with age, pubescent, often spine-tipped. Leaves on short branchlets mostly fascicled, those on annual ones usually alternate; petiole 2–5 mm, glabrous; leaf blade broadly elliptic, suborbicular, or obovate, 8–15 × 6–10 mm, both surfaces glabrous, base cuneate, margin shallowly obtusely serrate, apex obtuse and sometimes mucronate; secondary veins ca. 4 on either side of midvein. Flowers solitary, rarely several fascicled on short branchlets. Pedicel very short, not much elongated in fruit, glabrous. Hypanthium campanulate, 3–4 mm, outside glabrous. Sepals oblong, nearly as long as hypanthium, outside glabrous, apex abruptly mucronate. Petals pink, obovate, 5–7 mm. Stamens many, unequal in length. Ovary pubescent. Style slender, ± as long as stamens, pubescent. Drupe broadly ovoid-globose, 1.2–1.5 × 1–1.2 cm, pubescent, apex acute; mesocarp thin, separating from endocarp and splitting at maturity; endocarp ovoid, 0.8–1.3 cm, surface smooth, shallowly furrowed but not pitted, ventral suture flattened, base asymmetric, apex mucronulate. Seed pale brown, broadly compressed ovoid. Fl. May–Jun, fr. Aug–Sep.

Hill lands in desert or desert grasslands, stony slopes, dry river beds; 1000--2400 m. Gansu, Nei Mongol, Ningxia [Mongolia].